Zusammenfassung der Ressource
GCSE Physics Unit 1 AQA
- Energy transfer by heating
- Infrared radiation
- Infrared radiation is
energy transfer by
electromagnetic waves
- All objects emit infrared radiation
- The hotter an object is the more
infrared radiation it emits in a
given time
- Surfaces and radiation
- Dark matt surfaces emit infrared
radiation more quickly than light,
shiny surfaces
- Dark matt surfaces absorb
infrared radiation more quickly
than light, shiny surfaces
- Light shiny surfaces reflect
more infrared radiation
than dark, matt surfaces
- States of matter
- Flow, shape, volume and density are
the properties used to describe each
state of matter
- The particles in a solid are held next to
each other, vibrating in their fixed
positions
- The particles in a liquid move about
a random and are in contact with
each other
- The particles in a gas move about
randomly are are much farther apart
than particles in a solid or liquid
- Conduction
- Metals are the best conductors
- Materials such as wool and
fibreglass are good insulators
- Conduction in a metal is mainly
due to free electrons
transferring energy inside the
metal
- Non-metals are poor
conductors because they
do not contain free
electrons
- Convection
- Convection is the
circulation of a fluid
(liquid or gas) caused by
heating it
- Convection takes
place only in liquids
and gases (fluids)
- Heating a liquid or a gas
makes it less dense so it
rises and causes
circulation
- Evaporation and condensation
- Evaporation is when a liquid turns into a gas
- Condensation is when a gas
turns into a liquid
- Energy transfer by design
- The rate of energy transfer to
or from an object depends on:
- The shape, size and type of material
of the object
- The materials the object is
in contact with
- The temperature difference between the object and its surroundings
- specific heat capacity
- The greater the mass of an object, the
more slowly its temperature increases
when it is heated
- The rate of temperature change in a
substance when heated depends on the
energy transferred to it, its mass and its
specific heat capacity
- Heating and Insulating buildings
- The rate of energy transfer to or from our homes can be reduced
- U-values tell us how much energy per
second passes through different
materials. The lower the U-value the
better the materials as an insulator
- Solar heating panels do not use fuel to
heat water but they are expensive to
buy an install